The Douglas B-66 Destroyer was developed during the early 1950s for the US Air Force as a jet-powered replacement for the World War II-vintage Douglas A-26 Invader, the North American B-45 Tornado, and the Martin B-57 Canberra. Air Force specifications called for the new jet bomber to deliver a 10,000 pound payload (including “special” weapons) with 1,000 nautical mile range.
Developed from the Douglas A-3 Skywarrior built for the US Navy, the B-66 was originally intended to be essentially an A-3 with only the Navy-specific equipment required for carrier operations, such as folding wings and vertical stabilizer, arresting gear, and catapult bridle hooks, removed from the Air Force B-66. But the Destroyer was eventually modified so many times that by the time the aircraft reached operational status with the Air Force the two jets shared very few common parts and the B-66 outweighed the A-3 by a little bit more than 10,000 pounds.
The Air Force requirement for low altitude operations required additional strength in the fuselage and wings. The B-66 wing had a revised layout with increased area yielding greater lift, a thinner cross-section, revised incidence angle, and revised ailerons, spoilers, and flaps. B-66 hydraulic and fuel systems were revised along with the landing gear, which were equipped with bigger tires for rough field operations. The B-66 nose and canopy were distinctive due to the presence of the ejection seats, a different radar system, and the required larger radar antenna.
The use of Allison J71 turbojet engines and the presence of ejection seats for the crew of three in the B-66 were the two primary operational differences between the two aircraft. The A-3 was powered by Pratt & Whitney J57 turbojets and lacked ejection seats for the crew. Those J71 engines would prove to be the major limiting factor in the operational success of the B-66.
The Air Force opted for the under-powered J71 engines instead of Pratt & Whitney J57s because other aircraft in production and in planning at the time, such as the Boeing B-52 Stratofortress strategic bomber, the Boeing KC-135 Stratotanker for Strategic Air Command (SAC) as well as the North American F-100 Super Sabre, the McDonnell F-101 Voodoo, and the Convair F-102 Delta Dagger for Tactical Air Command (TAC) and Air Defense Command (ADC), all had priority over for engine procurement over the B-66. The Navy needed J57 engines for the Vought F-8 Crusader.
The reconnaissance version of the B-66, designated RB-66A, was actually the first version of the aircraft to go into production and was later produced concurrently with the bomber version of the airframe. The initial five RB-66A aircraft produced by Douglas had so many problems that the Air Force considered cancellation of the program and began a search for a replacement. Because fixes for most of the issues, such as poor handling, restricted outward vision, malfunctioning landing gear doors, wing vibrations and buffeting, and a propensity for pitching up had been identified, the program was allowed to continue.
Like the A-3, the B-66 was adapted for use in multiple roles. The RB-66A and RB-66B were all-weather reconnaissance versions. The B-66B was the straight bomber version, actually developed from the RB-66B. The RB-66C, EB-66C, and EB-66E were all electronic reconnaissance and countermeasures versions with four electronic warfare officers housed in the bomb bay sitting on downward-firing ejection seats added to the crew. The WB-66D was a weather reconnaissance version.
Although the Destroyer was originally designed as a bomber, it never dropped a bomb in combat. The majority of the 72 B-66s built by Douglas ended up being modified to one of the specialized electronic warfare or photo reconnaissance versions. Two B-66Bs were modified for parachute test drops of models of Gemini and Apollo space capsules. These two aircraft had their bomb bay doors removed, with the capsules carried semi-externally.
The RB-66Bs that entered service with the US Air Force were first used for night photo reconnaissance in Europe. Based in West Germany and in the United Kingdom, these aircraft played key roles in the determination of Soviet strength and dispositions along the Iron Curtain when that knowledge was critically important. RB-66Cs also carried out missions over Cuba during the Missile Crisis of 1962.
The RB-66C and RB-66E could be distinguished from the other B-66 variants by the wingtip electronic countermeasures (ECM) pods as well as the forest of blade antennae mounted to the aircraft and an extended boat tail housing additional ECM gear. These were the aircraft that carried the ECM jamming load for the first few years of the war in Vietnam.
A 19th Tactical Reconnaissance Squadron (TRS) RB-66C was shot down over East Germany by a Soviet MiG-21 on March 10th 1964. The aircraft was flying a photo-reconnaissance mission out of Toul-Rosières Air Base in France and crossed over the border after suffering a compass malfunction. The crew survived their ejection from the stricken jet and were taken prisoner by the East Germans before repatriation.
A 42nd Tactical Electronic Warfare Squadron (TEWS) EB-66C was shot down by AS-2 Guideline surface to air missiles (SAMs) just south of the Demilitarized Zone (DMZ) on April 2nd 1972. One surviving crew member, Lieutenant Colonel Iceal Hambleton (callsign Bat 21), made it to the ground and spent the next eleven days evading capture before being returned to American control on the 13th of April.
Air Force B-66s were all retired by the end of 1975. Of course the A-3 Skywarrior, forever linked to the B-66 Destroyer although in actual use a very different aircraft, continued to serve the Navy and the country until 1991 and flew defense contractor test flights for many more years after that.